System.setSecurityManager(new SecurityManager() {
                        @Override
                        public void checkPermission(Permission perm) {
                            if ("setSecurityManager".equals(perm.getName())) {
                                throw new SecurityException("You cannot replace this security manager!");
                            }
                        }

//sys	Mprotect(b []byte, prot int) (err error)
//sys	msync(b []byte, flags int) (err error)
//sys	Munlock(b []byte) (err error)
//sys	Munlockall() (err error)
//sys	Open(path string, mode int, perm uint32) (fd int, err error)
//sys	Pathconf(path string, name int) (val int, err error)
//sys	pread(fd int, p []byte, offset int64) (n int, err error)
//sys	pwrite(fd int, p []byte, offset int64) (n int, err error)

//sys	Mknodat(dirfd int, path string, mode uint32, dev int) (err error)
//sys	Nanosleep(time *Timespec, leftover *Timespec) (err error)
//sys	Open(path string, mode int, perm uint32) (fd int, err error)
//sys	Openat(dirfd int, path string, mode int, perm uint32) (fd int, err error)
//sys	Pathconf(path string, name int) (val int, err error)
//sys	pread(fd int, p []byte, offset int64) (n int, err error)

	MOVW.CS	$0, R8 // crash on syscall failure
	MOVW.CS	R8, (R8)
	JMP	0(PC)

TEXT runtime·open(SB),NOSPLIT|NOFRAME,$0
	MOVW name+0(FP), R0	// arg 1 name
	MOVW mode+4(FP), R1	// arg 2 mode
	MOVW perm+8(FP), R2	// arg 3 perm
	MOVW $SYS_open, R7
	SWI $0
	MOVW.CS	$-1, R0
	MOVW	R0, ret+12(FP)
	RET

TEXT runtime·read(SB),NOSPLIT|NOFRAME,$0
	MOVW fd+0(FP), R0	// arg 1 fd
	MOVW p+4(FP), R1	// arg 2 buf

cc args...
	run the platform C compiler


cd dir
	change the working directory


chmod perm paths...
	change file mode bits

	Changes the permissions of the named files or directories to
	be equal to perm.
	Only numerical permissions are supported.

cmp [-q] file1 file2
	compare files for differences

	sysvicall2(&libc_clock_gettime, _CLOCK_MONOTONIC, uintptr(unsafe.Pointer(&ts)))
	return ts.tv_sec*1e9 + ts.tv_nsec
}

//go:nosplit
func open(path *byte, mode, perm int32) int32 {
	return int32(sysvicall3(&libc_open, uintptr(unsafe.Pointer(path)), uintptr(mode), uintptr(perm)))
}

func pthread_attr_destroy(attr *pthreadattr) int32 {
	return int32(sysvicall1(&libc_pthread_attr_destroy, uintptr(unsafe.Pointer(attr))))
}

	AVPK
	AVPKH
	AVPKF
	AVPKG
	AVPKLS
	AVPKLSH
	AVPKLSF
	AVPKLSG
	AVPKLSHS
	AVPKLSFS
	AVPKLSGS
	AVPKS
	AVPKSH
	AVPKSF
	AVPKSG
	AVPKSHS
	AVPKSFS
	AVPKSGS
	AVPERM
	AVPDI
	AVPOPCT
	AVREP
	AVREPB
	AVREPH
	AVREPF
	AVREPG
	AVREPI
	AVREPIB
	AVREPIH
	AVREPIF
	AVREPIG
	AVSCEF
	AVSCEG
	AVSEL
	AVSL
	AVSLB
	AVSLDB
	AVSRA

	AVCMPGTSH
	AVCMPGTSHCC
	AVCMPGTSW
	AVCMPGTSWCC
	AVCMPGTSD
	AVCMPGTSDCC
	AVCMPNEZB
	AVCMPNEZBCC
	AVCMPNEB
	AVCMPNEBCC
	AVCMPNEH
	AVCMPNEHCC
	AVCMPNEW
	AVCMPNEWCC
	AVPERM
	AVPERMXOR
	AVPERMR
	AVBPERMQ
	AVBPERMD
	AVSEL
	AVSPLTB
	AVSPLTH
	AVSPLTW
	AVSPLTISB
	AVSPLTISH
	AVSPLTISW
	AVCIPH
	AVCIPHER
	AVCIPHERLAST
	AVNCIPH
	AVNCIPHER

		t = t.Elem()
	}
	if t.IsArray() {
		n.SetBounded(bounded(r, t.NumElem()))
		if base.Flag.LowerM != 0 && n.Bounded() && !ir.IsConst(n.Index, constant.Int) {
			base.Warn("index bounds check elided")
		}
	} else if ir.IsConst(n.X, constant.String) {
		n.SetBounded(bounded(r, int64(len(ir.StringVal(n.X)))))
		if base.Flag.LowerM != 0 && n.Bounded() && !ir.IsConst(n.Index, constant.Int) {
			base.Warn("index bounds check elided")
		}

		if s != "" {
			return s
		}
	}
	return "errno " + itoa.Itoa(int(e))
}

func (e Errno) Is(target error) bool {
	switch target {
	case oserror.ErrPermission:
		return e == EACCES || e == EPERM
	case oserror.ErrExist:
		return e == EEXIST || e == ENOTEMPTY
	case oserror.ErrNotExist:
		return e == ENOENT
	case errorspkg.ErrUnsupported:
		return e == ENOSYS || e == ENOTSUP || e == EOPNOTSUPP
	}